Pyridyl amines have been used to prepare Group 4 complexes which are useful transition metal components for use in the polymerization of alkenes, see for example US 2002/0142912; U.S. Pat. No. 6,900,321; and U.S. Pat. No. 6,103,657, where the ligands have been used in complexes in which the ligands are coordinated in a bidentate fashion to the transition metal atom.
WO 2005/095469 shows catalyst compounds that use tridentate ligands through two nitrogen atoms (one amido and one pyridyl) and one oxygen atom.
US 2004/0220050A1 and WO 2007/067965 disclose complexes in which the ligand is coordinated in a tridentate fashion through two nitrogen (one amido and one pyridyl) and one carbon (aryl anion) donors.
A key step in the activation of these complexes is the insertion of an alkene into the metal-aryl bond of the catalyst precursor (Froese, R. D. J. et al., J. Am. Chem. Soc. 2007, 129, pp. 7831-7840) to form an active catalyst that has both five-membered and a seven-membered chelate rings.
WO 2010/037059 discloses pyridine containing amines for use in pharmaceutical applications.
US 2010/0227990 A1 discloses ligands that bind to the metal center with a NNC donor set instead of an NNN or NNP donor set.
WO/0238628 A2 discloses ligands that bind to the metal center with a NNC donor set instead of an NNN or NNP donor set.
Guerin, F.; McConville, D. H.; Vittal, J. J. Organometallics 1996, 15, p. 5586 discloses a ligand family and group 4 complexes that use a NNN-donor set, but do not feature 7-membered chelate ring or either of dihydroindenyl- and tetrahydronaphthalenyl-groups.
U.S. Pat. No. 7,973,116, U.S. Pat. No. 8,394,902, US 2011-0224391, US 2011-0301310 A1, and U.S. Ser. No. 61/815,065, filed Apr. 23, 2013 disclose pyridylamido transition metal complexes that do not feature dihydroindenyl- or tetrahydronaphthalenyl-groups.
References of interest also include: 1) Vaughan, A; Davis, D. S.; Hagadorn, J. R. in Comprehensive Polymer Science, Vol. 3, Chapter 20, “Industrial catalysts for alkene polymerization”; 2) Gibson, V. C.; Spitzmesser, S. K. Chem. Rev. 2003, 103, 283; 3) Britovsek, G. J. P.; Gibson, V. C.; Wass, D. F. Angew. Chem. Int. Ed. 1999, 38, 428; 4) WO 06/036748; and 5) McGuire R. et al. Levason Bill et al, Platinum(II) polypyridines: A tale of two axes”, Coordination Chemistry Reviews, Elsevier Science, Amsterdam, NL, vol. 254, no. 21-22, 1 Nov. 2010, pp. 2574, 2583, XP027279924, ISSN: 0010-8454.
There still is need for adding synthetic routes to widen the range of catalyst complexes that may be prepared and broaden their performance in alkene polymerization. The performance may be varied in respect of the amount of polymer produced per amount of catalyst (generally referred to as the “activity”) under the prevailing polymerization conditions; the molecular weight and molecular weight distribution achieved at a given temperature; and/or the placement of higher alpha-olefins in terms of the degree of stereoregular placement. In particular, improvement of catalyst activity is of interest in the industry as it directly impacts economic feasibility.